For US-UDFPS: update shouldHandleTouches outside of view lifecycle

Ultrasonic UDFPS touches go directly to the HAL instead
of being forwarded via SystemUI. Therefore, for US-UDFPS,
SysUI doesn't need to wait until the UDFPS view is added
before informing the HAL that it can listen for touches.

As a result, when the device goes to sleep, ultrasonic UDFPS
can start updating shouldHandleTouches immediately before
the udfps-view is added. This decreases the delay
of starting UDFPS listening when the device initially starts
going to sleep.

Test: atest UdfpsOverlayInteractorTest
Test: enroll US-UDFPS; press power button (from home screen or
app), attempt UDFPS immediately, observe UDFPS can be used
quicker than before this CL
Flag: com.android.systemui.new_dozing_keyguard_states
Bug: 391771923

Change-Id: Id952649a71c341efbecce74e4470bef03378c6cd